I have a list box that goes to a path and shows all files in the path. I want to hide a certain file from being seen in the list box GUI. Is there a way to hide from view. I am still using the file in the code. Please see the code below I am using load the list of files into the GUI.

When you use 'get-childitem', you'll have the file "extention" property available. This way you can narrow the selection to be listed.
Of course, it's possible to use both the '-filter' parameter or use the "... | where-object{.." to narrow the files.

If you need to selectively show and hide or selectively show files in a listbox or other data bound controls then you can just set the filter on the datatable the control is bound to. This saves requerying for data. The datatable has a defaultview with a "RowFilter" property that can be set to filter the visible rows:

Note that "SuspendLayout" is used to control flicker on slow processors. Using a table to load a list box does not cause flicker on nearly all modern systems. Using "Add" to load a very large ListBox may cause some small amount of flicker. I recommend not using it and not using "Add" when not needed. Use an object data source or table.